1. Field of the Invention
The present invention relates to a method for finding the correlation between two subjects, in particular, to a method for finding the correlation between tool prevention maintenance (PM) and the product yield of the tool.
2. Description of Related Art
In terms of equipment manufacturing, the prevention maintenance (PM) for a tool is very important. A timely prevention maintenance schedule can effectively increase the productivity of the tool, the availability of the tool, and the associated yield of the overall equipment manufacturing. On the other hand, an improper prevention maintenance schedule besides resulting in decreased productivity and decreased yield for the associated tool, may also cause the tool itself to have a chance of malfunctioning.